Kingdoms are classified into three Domains and into one of the six kingdoms of life.
Survival of the fittest is talking about when you have traits that will help you, you are more likely to live rather than not having those traits. For example, a bird that swims a lot has webbed feet so it has a better chance of surviving then a bird who does not have webbed feet
Hard, dense bone tissue that is beneath the outer membrane of bone <span />
